1. Adam, D. B. (1923) J. Dept. Agr., Victoria21 307–317.
2. Airola, E. V. (1941) Papp. Tavaratidskr. Finl.23 112–114, 116–118, 120–122, 124, 126, 128–129.
3. Alwood, W. A. (1908) Bur. Chem. U.S.D.A. Bull.111 1–28.
4. Anon. (1925) Nature116, 187.
5. Anon. (1930) Rept. Calif. Agr. Exp. Sta. July 1, 1928 — June 30, 1929, 123 pp.